Inspection
300 CE, D, E, SD, SL & TE & 1992 300 SEBall joints are maintenance free. If a damaged ball joint boot is discovered the ball joint must be replaced. Check for a firm seat in the control arm. Check the sleeve for cracks and damage, then the wire retainer for proper seating. Place a six inch (150 mm) long tube onto steering knuckle pins. Pins should move backward and forward without play, jamming or a grating noise.
300SEL & 1989-91 300SE
These models are equipped with a ball joint and guide joint.
The ball joints are maintenance free. If a damaged ball joint boot is discovered the ball joint must be replaced. Place a six inch (150 mm) long tube onto steering knuckle pins. Pins should move backward and forward without clearance, binding or rasping noise. Check ball joint sleeves for cracking and damage.
The guide joint is located in the control arm. Check the sleeve for cracks, damage or leaking. If guide joint is found faulty, the upper control arm assembly must be replaced.